Luis Javier Sandoval via Getty ImagesCollyer is believed to have been attacked by a great white shark

Nine News

Although she was an advanced open water diver, it is understood that she had not been out diving for a number of weeks when the tragedy took place.

Collyer was the second person killed by a shark in Western Australia in less than a week. On Tuesday, a surfer's leg was bitten off by a shark about 60 miles (100km) south of where the Collyer was mauled.